In various applications, the accurate detection of lighting conditions may be helpful. For example, most computation and communication devices such as smart phones, laptop computers, tablets, and the like, include a display. Exemplary displays may be comprised of a liquid crystal display (LCD) or organic light-emitting diodes (OLED). Because these devices may be used in different lighting conditions, the display brightness must be adjusted based on detected lighting conditions. If the display is to dim in bright conditions, it may be unreadable. Conversely, if the display is too bright for the ambient conditions, it may be uncomfortable to view. Thus, by determining the lighting conditions, the display brightness may be adjusted so as to allow a good user experience while minimizing power usage.
In an exemplary device, ambient light sensors comprise arrays of photodiodes that detect visible and infrared light (IR), and photodiodes that detect only IR light. These are utilized to determine the incident light intensity (illuminance) so that the brightness of the display can be properly adjusted. Since the ambient light sensors are typically disposed within the device, it is possible for certain incident angles of light to introduce errors into the illuminance determination due to shadowing. This effect is most pronounced when the device is used in the sun, or in dark rooms with incandescent lighting, and can cause the brightness control software to make the display too dark.